Code-switching effects in bilingual word recognition: a masked priming study with event-related potentials

Two experiments tested language switching effects with bilingual participants in a priming paradigm with masked primes (duration of 50 ms in Experiment 1 and 100 ms in Experiment 2). Participants had to monitor target words for animal names, and ERPs were recorded to critical (non-animal) words in L1 and L2 primed by unrelated words from the same or the other language. Both experiments revealed language priming (switching) effects that depended on target language. For target words in L1, most of the language switch effect appeared in the N400 ERP component, with L2 primes generating a more negative going wave than L1 primes. For L2 target words, on the other hand, the effects of a language switch appeared mainly in an earlier ERP component (N250) peaking at approximately 250 ms post-target onset, and showing greater negativity following an L1 prime than an L2 prime. This is the first evidence for fast-acting language-switching effects occurring in the absence of overt task switching.     

Co-activation of syntax in bilingual language production

We report four experiments that examined whether bilinguals’ production of one language is affected by the syntactic properties of their other language. Greek–English and English–Greek highly proficient fluent bilinguals produced sentence completions following subject nouns whose translation had either the same or different number. We manipulated whether participants produced completions in the same language as the subject (the source language; one-language production) or the other language (the non-source language; two-language production), and whether they used only one language or both languages within the experimental session. The results demonstrated that the grammar systems of both languages were activated during both one-language and two-language production. The effects of the non-source language were particularly enhanced in two-language utterances, when both languages were used in the experiment, and when it was the bilinguals’ native language. We interpret our results in terms of a model of bilingual sentence production.